Leukoplakia :
Leukoplakia is a precancerous lesion with thick white patches and a flat or raised surface inside the mouth. It may usually seen on the tongue, gums, and cheeks. Factors that cause leukoplakia are smoking, alcohol, poor immune system, injury to the cheeks from biting, rough and uneven teeth, unfit dentures, and genetic mutations. Types include homogenous leukoplakia and nonhomogenous leukoplakia. Subtypes include proliferative verrucous leukoplakia and oral hairy leukoplakia. Diagnosis can be made by doing biopsies and sending the sample to pathologists to examine under a microscope. Treatment can be done using lasers, photodynamic therapy, cryotherapy, and electrocauterization.